Genesis 42:15-20

MSTC(i)15 Hereby ye shall be proved. For by the life of Pharaoh, ye shall not go hence, until your youngest brother be come hither.
16 Send therefore one of you and let him fetch your brother, and ye shall be in prison in the mean season. And thereby shall your words be proved, whether there be any truth in you: or else by the life of Pharaoh, ye are but spies."
17 And he put them inward three days.
18 And Joseph said unto the third day, "This do and live, for I fear God.
19 If ye mean no hurt, let one of your brethren be bound in the prison, and go ye and bring the necessary food unto your households,
20 and bring your youngest brother unto me: that your words may be believed, and that ye die not." And they did so.